1. Field of the Invention
The present invention relates to an improved igniter propellant composition that ignites and burns at the low pressures of space vacuum to provide hot combustion gases for reliably igniting a rocket motor.
2. Description of the Prior Art
Prior art propellant compositions that meet the requirements of ease of ignition under vacuum conditions in space and which burn steadily at reduced pressures up to two or three pounds per square inch absolute (psia) either use liquid burning rate catalysts or plasticizers. Such liquid catalysts or liquid plasticizers are used in order to obtain a sufficiently high solids level of finely ground ammonium perchlorate to provide processable propellants of sufficient energy to act as energetic igniter compositions.
A problem with such prior art propellants is that the liquid portions thereof are too volatile for the high vacuum conditions found in space in consequence of which liquids diffusing from the propellant can result in changes in the rocket motor burning characteristics. Any volatile materials can also migrate to other assemblies or space experiments that may be stored in the vicinity causing contamination problems.